This chapter is really important to read. It explains fundamental concepts of DPL.
There are two modes to invoke DPL; each of them has its advantages and disadvantages.
DPL has a mechanism to substitute variables, it has different output modes,
can accept variables from the URL, etc.
So, please read.

define a section with multiple occurrences as dominant, i.e. each piece of contents of this section (which is associated with a template call or a chapter within the original document) will create a separate output line.

To control the output of the headings in a DPL with complex/multi-parameter ordermethods. (No effect with single-param ordermethods.) For ordermethod=method1,method2,..., method1 is used for headings. E.g. headingmode affects category headings in ordermethod=category,title (2-param ordermethod). See also headingcount

Adds attributes to HTML list elements, depending on mode (HTML element is ol for ordered, ul for unordered, div for others). Can be used with pseudomode=inline where inline text contains one or more <BR/>.

Not applicable to mode=category or mode=inline (with no <BR/> in inline text).

To limit the number of characters of the title to display. If the page title (this does not include the namespace or any other prefix before the title) is bigger than the titlemaxlength value, the title is truncated and ended by '...'.

Define a row layout for the output. A "row" is a group of output lines for which the heading is repeated. If you do not know how big your result will be, it may be better to use the "rowsize" parameter.

Requires ordermethod=[...,]firstedit or ordermethod=[...,]lastedit (where the [...,] signifies a complex ordermethod with extra parameters). If firstedit (lastedit), 'adduser=true' displays the user who made the first (last) revision of the page. In this way the parameter is equivelent to the addauthor (addlasteditor) parameter (see below).

Shows the date/time the article got added to one of the listed include categories. If there are more than one categories listed and an article belongs to more than one of them, the result is ambiguous.

From a logical point of view it is recommended to include one category only with 'category' parameter or to make sure that each of the article in the result belongs to only one of the categories listed.
Conflicts with other "add*date" (addeditdate, etc.) parameters to avoid confusion.

include pages (whole content) or include certain sections of articles or template parameters.

This functionality is based on the ideas and work of Steve Sanbeg and his extension Labeled Section Transclusion. DPL comes with a modified version of Sanbeg´s source, so there is no need for additional installation.

Delimit the size of an included article to a maximum of [n] characters of wiki source text or less.

Care is taken to respect pairs of braces and brackets as far as possible. Otherwise we might confuse the result by half-cut syntax elements of transcluded sections. Therefore the output might be shorter or even larger than [n] characters.

Select pages with a title matching at least one of the specified patterns. The patterns are used as a LIKE argument in an SQL query. Namespaces are ignored as the namespace parameter can be used to further narrow the selection.

Select pages with a title matching the specified regular expressions. The pattern will be used as a REGEXP argument in a SQL query. Namespaces are ignored as the namespace= parameter can be used to further narrow the selection.

Select pages with a title NOT matching any of the specified patterns. The patterns are used as a LIKE argument in a SQL query. Namespaces are ignored as the namespace= parameter can be used to further narrow the selection. Normally you would want to use this selection only in combination with other criteria. Otherwise output could become huge.

Select pages with a title that does NOT match the specified regular expression. The expression will be used as a REGEXP argument in a SQL query. Namespaces are ignored as the namespace= parameter can be used to further narrow the selection. Normally you would want to use this selection only in combination with other criteria. Otherwise output could become huge.

shows all revisions which were created after the specified date. The date of each revision will be shown (and will be available as %REVISION% in mode=userformat). If there was no new revision of an existing article after the specified date that article will not appear in the output.